The invention relates to an insertion unit that for the first time allows gaining access to the left ventricle of the heart, via the tissue forming the wall of the right ventricle and via the ventricular septum.
Access to the left ventricle is a major concern both in the field of heart diagnostics and in heart therapy. Such an access would allow a great number of new therapies and diagnostic methods and/or would simplify the performing of well-known therapies and diagnostic methods. Therefore the invention also relates to devices using said insertion unit.
Examples for suitable devices are given below. The listed devices are by no means exhaustive.                Device for gaining access to all Chambers of the heart and to the abdominal region.        Device for stimulation and defibrillation of the heart.        Device for cardiac valve replacement and/or the dilatation of the replaced valves.        Device for repairing cardiac valves and for improving the mitral valve geometry.        Device for ventricle size reduction in case of a pathological ventricle enlargement.        Ventricular assist device (Heart pump)        Device for taking blood from the left ventricle and for supplying the heart muscle tissue with blood via the coronary arteries (Therapy of coronary stenosis, bypass operation).        Device for improving the myocardial blood flow.        Device for gaining access to the aortic valve by avoiding abrasion of calcified arterial plaque.        Device for monitoring post operation bypass blood flow.        Device suitable as a port to the heart chambers.        Device for mapping a heart chamber.        Device for treating atrial fibrillation with RF ablation.        Device for examining the inner walls of the heart chamber and of blood vessels        Device for repairing the ventricular septum (VSD) after pathological sudden rupture.        Device for gaining access to the pulmonary and aortic artery.        Device for transmitting cell material into the heart chambers        Device for monitoring the cardiac output by measuring impedance changes.Access to the Left and Right Ventricle        
The problem underlying the present invention is to gain access to the left ventricle without injuring the tissue forming the wall of the left ventricle. Moreover, the insertion of trocars, catheters, electrodes and implantable medical devices of all kind both into the left as well as into the right ventricle shall be made possible or shall be simplified.
The problem is solved by a new insertion unit allowing the above required access to the left ventricle. The access to the left ventricle via the muscle tissue of the right ventricle and the ventricular septum is particularly desirable because the pressure in the right ventricle is lower than in the left ventricle. Moreover the muscle tissue that makes up the wall of the left ventricle is about three times thicker than that of the right ventricle.
The invention thus relates to an insertion unit comprising a tubular shaft (FIG. 1) (5) with a lumen (8) extending there through, said shaft comprising distal, proximal and central sections, whereby the distal and proximal sections are disc-shaped extended thus forming each a double disc (1), (2) resp. (3) (4) and whereby the central section (50) links the distally placed double disc (1), (2) with the proximally placed double disc (3),(4), and whereby pressure valve (6) resp. (7) are fixed inside the shaft preferably on its distal and proximal end.
The used expression “disc-shaped” also includes related structures like umbrella-shaped, discus-shaped or ellipsoid-shaped. The double disc serves as a fixation device like an occlusion member.
The disc-shaped extensions (1), (2), (3) and (4) have a larger diameter than the tubular shaft (5), approximately five times to fifteen times greater.
The distally placed double disc (1), (2) is suitable for being implanted in the ventricular septum. The proximally placed double disc (3), (4) is suitable for being implanted in the heart muscle tissue of the right ventricle.
The double discs serve for placing and fixing the insertion unit into the ventricular septum resp. into the muscle tissue of the right ventricle. Due to its disc-shaped extensions, the insertion unit remains in position after its implantation and sliding is prevented.
The dimensions of the tubular shaft (5) are adapted to the anatomical structure between left and right ventricle.
For accessing the right ventricle the central section (50) has a lateral opening (Y-piece with valve). An access to the right ventricle or to the abdomen can also be achieved using an insertion unit comprising only double disc (1), (2) and a pressure valve fixed therein.
The present insertion unit consists of a biocompatible and flexible material. Each biocompatible material is suitable that may form a tubular shaft with disc-shaped extensions. It must be possible to fix at least two pressure valves, e.g. silicone valves, inside the shaft. The insertion unit must be foldable so that it can be inserted by means of a trocar.
Suitable materials are for example polymeric materials like silicone or polyurethane; metals like stainless steel, nickel-alloy MP35N or shape-memory materials like nitinol wires, nitinol strands, nitinol threads. The nitinol wires, strands and threads may be coated with polymeric material. Furthermore, shape-memory plastic threads, nitinol wires coated with other metals, e.g. nitinol wires coated with gold or platinum may also be suitable.
In a preferred embodiment the insertion unit is made of braided wires of shape-memory material (preferably nitinol) said wires and thus the whole insertion unit may form a common electrical pole, if connected to an Implantable Cardiac Defibrillator (ICD).
If the insertion unit is made of braided nitinol wires a tubular shaft is first braided, said shaft being deformed by heat or pressing in such a way that it forms disc-shaped extensions (1), (2), (3) and (4). These discs can be formed by braiding a single braid or a double braid lying on top of each other.
Shaft (5) of the insertion unit may completely or partly be coated with biocompatible polymeric material, e.g. silicone. Such a coating prevents blood intrusion into the inner braided part. The coating can be inside or outside. Preferably the central section (50) of the shaft is coated with biocompatible polymeric material. The term “coated with biocompatible polymeric material” also includes a polymer tube being pulled over the braided central section.
The proximal wire ends of the braided tubular shaft can be fixed by a sleeve or holder that has an opening too, so that lumen (8) is continuous.
However, the insertion unit can also be braided in two parts and be welded in the central section. Such a direct welding is described in WO2012095314.
The insertion unit can also consist of two pieces. In a two-piece design the central section (50) of the tubular shaft (5) is made from another material or has another design than the distal and proximal sections. In one embodiment the central section (50) of the tubular shaft is completely or partly coil shaped, said coil serving as spring. Said coil may be coated inside and/or outside with silicone or with other suitable biocompatible material or the coil is covered with a silicone tube.
The lumen (8) extends through the whole tubular shaft of the insertion unit in axial direction. At least two pressure valves are fixed inside the shaft preferably on its distal and proximal end. The distally placed pressure valve (6) is important in order to prevent the blood flow from the left to the right ventricle. The proximally placed pressure valve is important to prevent bleeding through the puncture of the right ventricle. The pressure valves are preferable silicone valves that are commercially available in many shapes and sizes. Suitable valves can be bought from the company Minivalve Int. B.V. for instance.
The tubular shaft (5) may be longitudinally extended thus forming an extended shaft (51). Said extended shaft may also be coated with a biocompatible polymeric material. The extended shaft may also be coil shaped similar to the central section.
The thus extended shaft comprises a further double disc (53),(54) with pressure valve (55) at its proximal end. The thus obtained insertion unit comprises three double discs being linked by the central section resp. the extended section of the shaft. The thus obtained insertion unit is suitable for gaining access to the left ventricle via the abdomen, the right ventricle and the ventricular septum.
The insertion unit may be a permanent implant. It can grow into the surrounding tissue like already known septal Occluder.
If desired, one or several sensors e.g. pressure sensors can additionally be fixed inside the shaft of the insertion unit.
In one embodiment, the insertion unit consists completely or partly of biocompatible synthetic material like silicone or polyurethane.
In another embodiment, the insertion unit consists completely or partly of a metal coil.
In a preferred embodiment the whole insertion unit is braided of nitinol wires. The insertion unit thus comprises a braided tubular shaft (5) of nitinol wires with a lumen (8) extending there through, said shaft comprising distal, proximal and central sections, whereby the distal and proximal sections are disc-shaped extended thus forming each a double disc (1), (2) resp. (3) (4) and whereby the central section (50) that links the distally placed double disc (1), (2) with the proximally placed double disc (3),(4) is coated with a biocompatible polymeric material, and whereby pressure valve (6) resp. (7) are fixed inside the shaft on its distal and proximal end.
Surgical threads may be woven into the proximal braiding. The threads can be tied together with a knot and serve as additional fixing of the double disc and as sealing of the muscle tissue forming the heart wall.
The insertion unit according to the invention can be used to insert a number of medical devices. Therefore the aim of the present invention is also to make devices available that are suitable for carrying out new therapies and diagnostic methods and/or that simplify carrying out well-known therapies and diagnostic methods. Examples of such devices are:
Devices for Stimulation and Defibrillation of the Heart (FIG. 6,7,8,9)
If the stimulation/defibrillation of the right and/or left ventricle is desired, the insertion unit according to the invention, which in this case must consist of a conducting material (e.g. nitinol), is connected to an ICD (Implantable Cardiac Defibrillator) to form one of the defibrillation electrodes or to form an indifferent electrode pole. The other stimulation or defibrillation poles can be standard implantable electrodes.
As shown in FIG. 8 the second defibrillation electrode can be an occlusion device placed in the atrial septum. The metal frame of the artificial valve may also serve as second defibrillation electrode (FIG. 9). The standard stimulation electrode or pace-sense electrode consisting of a lead provided with a pole at its distal end portion is inserted through the shaft of the insertion unit and guided to the left ventricle, fixed and connected to an ICD or pacemaker (FIG. 6). The lead runs inside the shaft.
If biventricular stimulation is desired, another stimulation electrode is inserted through the shaft of the insertion unit which in this case has a lateral opening. The electrode is guided to the right ventricle, fixed and connected to an ICD or pacemaker (FIG. 7). The number of stimulation electrodes is not limited. Depending of the number and the position of the pacing leads, one can use it as a one chamber pacing system or a biventricular stimulation system.
Every known unipolar or bipolar stimulation electrode or ICD electrode can be used. The distal pole of the electrode can be a screw type, for instance.
For the first time, biventricular stimulation is possible without the need of introducing the electrodes via the coronary sinus vein. The difficult positioning and fixation within the coronary sinus can be avoided. It will therefore reduce the number of so called “non responder”.
Device for Cardiac Valve Replacement and/or the Dilation of the Replaced Valve (FIG. 3, 4, 22)
The inventive insertion unit is combined with a trocar to push in a cardiac valve prosthesis. Standard procedure known as TAVI (Trans catheter Aortic Valve Implantation) is carried out. A catheter (trocar) is inserted through the shaft of the insertion unit. Before the new Aortic Valve can be placed, the present old valve has to be dilated with a balloon catheter in order to gain space for the new valve. A cardiac valve prosthesis is pushed through the trocar. The artificial valve mounted on a metal frame is fixed on a balloon and will be positioned directly inside the diseased valve. The standard TAVI procedure is normally carried out by entering through the tip of the left ventricle (the apex). Closing the opening of the left ventricle, which has to be done when using the common left ventricular approach, is a big surgical problem. The tissue around the opening of the heart is especially for old patients very soft and therefore very sensitive to any suture manipulation. With the inventive insertion unit one can eliminate this problem by entering the heart chamber through the right ventricle. If required the balloon is inserted via a guide wire with a distal filter to protect the brain arteries in order to avoid possible abrasion of calcified arterial plaque.
In order to open a narrow heart valve balloon valvotomy is commonly performed. Instead of a balloon a balloon-free dilatation catheter can be used having at its distal end a cage like expander having elongated expanding element as shown in FIG. 22.
Device for Ventricle Size Reduction (FIG. 11)
In order to reduce the ventricle size in case of a pathological ventricle enlargement, the insertion unit according to the invention is modified by reducing the number of distally placed discs (1), (2) to one disc (1), The distally placed disc (1) has fixation hooks (60) that can be fixed in the muscle tissue forming the wall of the left ventricle resp. in the ventricular septum. The central section (50) between the fixed disc (1) and the braided double discs (3) and (4) is elastic, similar to a spring. In FIG. 11 the central section is formed as a spring (61).
Device for Improving or Increasing the Cardiac Output
Electromechanical Device (FIG. 5)
A heart pump is inserted through the shaft of the inventive insertion unit and guided to the left ventricle and further to the ascending aorta. Suitable heart pumps are commercially available; for example the Impella®-Pump
Pneumatic Device (FIG. 17)
A pneumatic device is placed into an artificial blood vessel system, said system being combined with the present insertion unit as described in the following paragraph. A blood pump is placed into the artificial blood vessel in such a way that blood is sucked from the left ventricle and transported into the aorta (FIG. 17). This would provide benefits especially to patients waiting for a heart transplant.
Device for Taking Blood from the Left Ventricle and for Supplying the Heart Muscle Tissue with Blood Via the Coronary Arteries (FIG. 13, 14)
The combination of the inventive insertion unit with an artificial blood vessel system provides a device allowing a new and simplified bypass surgical technique.
The artificial blood vessel system consists of an unbranched or branched tube. One end of said tube is placed and fixed (e.g. by bonding) within the shaft of the insertion unit. The other end of the tube can be arranged around the heart. The tube is variable in length and shape so that the artificial blood vessel can be put around the heart (around the ventricles and/or the atria) partly or completely or can be guided to other organs in the abdomen as well. Every anastomosis typically used in surgery can be considered for fixing the artificial blood vessel on the heart tissue.
The artificial blood vessel has one or more small branches being connectable to a coronary artery and thus serving as bypass. The small branches are put over the blocked coronary artery and are sewed or bonded below the stenosis. These small branches serving as bypass have a smaller diameter than the tube of the artificial blood vessel system.
For treating coronary stenosis the artificial blood vessel is fixed on the heart tissue. After puncturing said artificial blood vessel the blocked coronary arteries are supplied with blood. The stenosis can thus be treated without removing a leg vein for instance. Moreover, the aorta does not have to be punctured. The operation is done without using a heart-lung-machine.
Suitable artificial blood vessels must consist of elastic biocompatible material, e.g. polytetrafluoroethylene (brand name Gore Tex) or polyester. Specialists are familiar with suitable materials and artificial blood vessels are commercially available (e.g. the product Dardik Biograft from the company Meadox Medical Inc. or products from the company Boston Scientific). Generally, each biocompatible elastic material is suitable.
Improvement of the Myocardial Blood Flow (FIG. 14)
The tube member of the artificial blood vessel may have a number of cannula- or thorn-like branches being arranged around the vessel and extending up into the myocardium like an injection needle in order to supply the myocardium with blood. Furthermore the formation of coronary vessels is activated.
Device for Taking Blood from the Left Ventricle and for the Simultaneous Stimulation and Defibrillation (FIG. 15, 16)
The above mentioned device combining the inventive insertion unit with an artificial blood vessel system can be equipped with implantable pacemaker leads so this unit is also suitable for stimulation and defibrillation.
As described above, the insertion unit, which in this case must consist of a conducting material (e.g. nitinol), is connected with an ICD to form one of the defibrillation electrodes or to form an indifferent electrode pole. At least one pacemaker lead is inserted via said insertion unit and guided to the left resp. right ventricle in order to establish a stimulation unit. By wrapping parts of the artificial blood vessel with a metallic coil a defibrillation electrode is formed. The defibrillation shock is given between the insertion unit and the metallic coil each being connected to an ICD.
Device for Monitoring Post Operated Bypass Blood Flow (FIG. 16)
The above mentioned device combining the inventive insertion unit with an artificial blood vessel system can be equipped with electrode poles or sensors that are in contact with a measuring unit and are suitable to monitor the blood flow in the bypass, e.g. by measuring the change of the electrical impedance between two sensors. The records can be saved and transferred by telemetry, if required. Any reduced blood flow is displayed immediately so that remedial action can be taken rapidly.
Examples for sensors are: ultrasonic sensors and/or flow sensors for controlling the blood flow; pressure sensors for controlling the blood pressure.
Device being Suitable as Port Catheter (FIG. 10)
The insertion unit according to the invention can also be connected with a subcutaneous port. For this purpose, the insertion unit is connected with the port chamber via flexible tubing. Medicine can thus be given into the ventricle via said port or blood samples can be taken as well.
Device for Inspecting the Inner Part of the Heart (FIG. 18)
Catheter type endoscopes with a video chip at the tip within a transparent balloon can be inserted through the shaft of the inventive insertion unit and guided to the inner part of the heart. By inflating the transparent balloon with CO2 gas or saline solution and pushing it to the desired area, the endoscope can inspect visually the inner parts of the heart.
Device for RF Ablation of Heart Tissue
One or several electrodes connected with a RF generator can be inserted through the shaft of the inventive insertion unit and guided to the left and/or right heart chambers to start the ablation procedure.
Device for Mapping a Heart Chamber
A steerable catheter with one or several mapping electrodes connected to a recording device can be inserted through the shaft of the inventive insertion unit and guided to the left and/or right heart chamber.
Device for Repairing the Ventricular Septum Defect (VSD) after Pathological Sudden Rupture (FIG. 19)
The immediate surgical closing of a sudden rupture of the ventricular septum is in most cases not possible, due to the tissue characteristic after the rupture.
A closing device is obtained by using enlarged braided occlusion discs (1), (2) as clamping means for closing ventricular septal defects or rupture. By adding some new tissue obtained by tissue engineering and/or nanotechnology developed or own harvested tissue material, the healing process could be improved.
Device for Gaining Access to the Pulmonary Artery and Right Atrium
The inventive insertion unit allows gaining access to the pulmonary artery and right atrium via the right ventricle.
Device for Transmitting Cell Material into the Heart Chambers
The inventive insertion unit allows transmitting cell material into the heart chambers. A carrier containing said cell material is inserted through the shaft of the inventive insertion unit and guided to the heart chambers.
Device for Improving the Mitral Valve Geometry by Reducing the Valve Area. (FIG. 20)
In order to reduce the amount of blood leaking backwards, the two leaflets of the mitral valve are—in known methods—partially clipped or sewn together. The inventive insertion unit allows a new mitral valve repair approach by using the insertion unit to insert a device for pushing anchors. A suitable device for pushing anchors is described in WO2007079952 corresponding to US20090012557. Instead of the presently used “clipping” procedure, or the presently used suture methods with one or more knots with the sutures, the new approach using the insertion unit results in reducing the size of the mitral (cardiac) valve as desired in a simplified procedure.
Device for Calculating and Monitoring the Cardiac Output. (FIG. 21)
A first electrical impedance measuring electrodes is inserted through the shaft of the insertion unit and fixed in the tissue of the left ventricle. A second impedance measuring electrodes is inserted through the shaft of the insertion unit and fixed in the tissue of the right ventricle. Both electrodes are connected to an electrical impedance measuring device thus forming an impedance measurement circuit. The cardiac impedance changes between systole and diastole. Those data are the basis to determine the stroke volume of the heart. An apparatus and a method for determining an approximate value for the stroke volume and the cardiac output of a person's heart is described in U.S. Pat. No. 6,511,438.
The present invention also refers to therapeutic and diagnostic methods that can be carried out with the above mentioned devices.
Many aspects of the invention can be better understood with reference to the following figures showing the insertion unit in detail and number devices using the insertion device.
The reference numbers represent:
AAortaCVCoronary veinLVleft ventricleRVright ventricleRFradio frequencyICD(Implantable Cardiac Defibrillator)(1, 2), (3, 4), (53, 54)double discs5tubular shaft6, 7, 55pressure valves8lumen9pressure sensor10catheter (trocar)11metal frame of the artificial valve12balloon13heart pump14, 15stimulation electrodes, pace sense electrodes (lead and pole)16, 17electrode lead18, 19impedance measuring electrodes20, 21, 22, 23defibrillation electrodes24, 25, 26, 27, 28, 31electrical connection line30pump motor31propeller shaft32electrical impedance measurement unit33pump control unit34pacemaker40port chamber41port catheter50central section of the tubular shaft51extended tubular shaft52surgical threads60fixing hook61, 62spring63sleeve70abdomen (abdominal wall, chest wall)80artificial blood vessel, tube member81small vessel branch,82cannula-like branches83tube member branch90electrode pole91control electrode (sensor)92, 93pair of electrodes, pair of sensors100hose pump110endoscope111endoscope-balloon112endoscope shaft113endo scope tip120new tissue material121anchor pusher122feed catheter for anchor pusher130dilation catheter131elongated expanding elements